Automated window blind

ABSTRACT

A window blind includes a shaft unit and a clutch unit. The shaft unit includes a pair of seat members, a shaft member, a tubular member, and a pushing member. The shaft member is mounted rotatably on the seat members. The tubular member is sleeved rotatably around the shaft member. The pushing member is sleeved securely on the shaft member. The clutch unit serves to connect and disconnect the shaft member and a pair of bobbins. When the shaft member is rotated in a first rotational direction, the clutch unit connects the shaft member and tubular member, thereby resulting in rotation of the tubular member in the first rotational direction. When the shaft member is rotated in a second rotational direction, the clutch unit disconnects the shaft member and the tubular member, and enables the pushing member to drive rotation of the tubular member in the second rotational direction.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a window blind, more particularly to an automated window blind.

2. Description of the Related Art

A conventional window blind for covering and uncovering a sunroof of an automobile includes a pair of seat members, a shaft member, a biasing spring, and a flexible screen body. The shaft member has opposite shaft end portions, each of which is mounted rotatably on a respective one of the seat members. The shaft member is rotatable relative to the seat members in a first rotational direction, and a second rotational direction opposite to the first rotational direction. The biasing spring serves to bias the shaft member in the second rotational direction. The screen body is wound on the shaft member.

In operation, when it is desired to cover the sunroof, an external pulling force is applied to the screen body such that the screen body is pulled away from the shaft member, thereby resulting in rotation of the shaft member in the first rotational direction against a biasing action of the biasing spring and unwinding of the screen body from the shaft member. At this time, when is it is desired to uncover the sunroof, the screen cover is released from the external pulling force, thereby resulting in rotation of the shaft member in the second direction due to the biasing force of the biasing spring and winding of the screen body on the shaft member.

The conventional window blind is disadvantageous in that it is manually operated, which causes inconvenience on the part of the user.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to provide a window blind that can overcome the aforesaid drawback of the prior art.

According to the present invention, a window blind comprises a shaft unit, a flexible screen body, a pair of bobbins, a pair of ropes, and a clutch unit. The shaft unit includes a pair of seat members, a shaft member, a tubular member, and a pushing member. The shaft member is mounted rotatably on the seat members. The tubular member is sleeved rotatably around the shaft member, and is formed with an inner protrusion that extends radially and inwardly therefrom. The pushing member is disposed in the tubular member, is sleeved securely on the shaft member, and is formed with an outer protrusion that extends radially and outwardly therefrom. The screen body is wound on the tubular member. The bobbins are disposed on opposite sides of the pushing member and are sleeved rotatably on the shaft member. Each of the ropes is wound on a respective one of the bobbins and is coupled to the screen body. The clutch unit serves to connect and disconnect the shaft member and the bobbins. Rotation of the shaft member in a first rotational direction enables the clutch unit to couple the shaft member and the bobbins, thereby resulting in rotation of the bobbins, winding of each of the ropes on the respective one of the bobbins to thereby permit the ropes to pull the screen body, rotation of the tubular member, and unwinding of the screen body from the tubular member. Rotation of the shaft member in a second rotational direction opposite to the first rotational direction enables the clutch unit to disconnect the shaft member and the bobbins. Further rotation of the shaft member in the second rotational direction enables the outer protrusion of the pushing member to abut against the inner protrusion of the tubular member, thereby resulting in rotation of the tubular member, winding of the screen body on the tubular member, rotation of the bobbins, and unwinding of each of the ropes from the respective one of the bobbins.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:

FIG. 1 is a fragmentary perspective view of the preferred embodiment of a window blind according to the present invention;

FIG. 2 is an exploded perspective, partly sectional view to illustrate a shaft unit of the preferred embodiment;

FIG. 3 is a partly sectional view of the preferred embodiment to illustrate rotation of a shaft member of the shaft unit in a first rotational direction;

FIG. 4 is a partly sectional view of the preferred embodiment to illustrate rotation of the shaft member of the shaft unit in a second rotational direction; and

FIG. 5 is a sectional view of the preferred embodiment to illustrate when a tubular member of the shaft unit being driven by a pushing member of the shaft unit to rotate in the second rotational direction.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, the preferred embodiment of a window blind according to this invention is shown to include a pair of elongate slide rails 64, a shaft unit 4, a flexible screen body 61, a pair of bobbins 55, a pair of pulleys 63, a pair of ropes 65, and a clutch unit 54.

The window blind of this embodiment is applied to cover and uncover a sunroof (not shown), in a manner that will be described hereinafter.

Each of the slide rails 64 has opposite first and second rail ends 641, 642, and is formed with a rail groove 640 that extends from the first rail end 641 to the second rail end 642 of a respective one of the slide rails 64.

With further reference to FIG. 2, the shaft unit 4 includes a pair of seat members 41, a shaft member 43, a tubular member 42, and a pushing member 44. Each of the seat members 41 of the shaft unit 4 is disposed proximate to the first rail end 641 of a respective one of the slide rails 64. The shaft member 43 of the shaft unit 4 is mounted rotatably on the seat members 41. The tubular member 42 of the shaft unit 4 is sleeved rotatably around the shaft member 43 of the shaft unit 4, and is formed with an inner protrusion 421 that extends radially and inwardly therefrom. The pushing member 44 of the shaft unit 4 is disposed in the tubular member 42 of the shaft unit 4, is sleeved securely on the shaft member 43 of the shaft unit 4, and is formed with an outer protrusion 441 that extends radially and outwardly therefrom.

The screen body 61 is wound on the tubular member 42 of the shaft unit 4, and has lateral ends 611, each of which is disposed in the rail groove 604 in a respective one of the slide rails 64, and a front end 612 that interconnects the lateral ends 611 of the screen body 61.

The window blind further includes a batten 62 that is connected to the front end 612 of the screen body 61.

The bobbins 55 are disposed on opposite sides of the pushing member 44 of the shaft unit 4 and are sleeved rotatably on the shaft member 43 of the shaft unit 4.

Each of the pulleys 63 is mounted rotatably on the second rail end 642 of a respective one of the slide rails 64.

Each of the ropes 65 is wound on a respective one of the bobbins 55, is trained on a respective one of the pulleys 63, and has an end that is connected to the batten 62.

The clutch unit 54 serves to connect and disconnect the shaft member 43 of the shaft unit 4 and the bobbins 55. In this embodiment, the clutch unit 54 includes a pair of couplers 543 and a pair of springs 542. Each of the couplers 543 of the clutch unit 54 is sleeved rotatably on the shaft member 43 of the shaft unit 4 and is connected to a respective one of the bobbins 55. Each of the springs 542 of the clutch unit 54 is disposed in a respective one of the couplers 543 of the clutch unit 54, is sleeved on and is in frictional contact with the shaft member 43 of the shaft unit 4, and has an end that is connected to a respective one of the couplers 543 of the clutch unit 54.

In operation, with further reference to FIG. 3, when the shaft member 43 of the shaft unit 4 is rotated in a first rotational direction, as indicated by arrow (A), this enables the springs 542 of the clutch unit 54 to contract in radial inward directions to thereby connect the shaft member 43 of the shaft unit 4 and the bobbins 55 through the couplers 543 of the clutch unit 54, respectively. This results in rotation of the bobbins 55, winding of each of the ropes 65 on the respective one of the bobbins 55 to thereby permit the ropes 65 to pull the screen body 61, rotation of the tubular member 42 of the shaft unit 4, and unwinding of the screen body 61 from the tubular member 42 of the shaft unit 4 to thereby cover the sunroof (not shown).

With further reference to FIG. 4, when the shaft member 43 of the shaft unit 4 is rotated in a second rotational direction opposite to the first rotational direction, as indicated by arrow (B), this enables the springs 542 of the clutch unit 54 to expand in radial outward directions to thereby disconnect the shaft member 43 of the shaft unit 4 and the bobbins 55. At this time, when the shaft member 43 of the shaft unit 4 is further rotated in the second rotational direction (B), this enables the outer protrusion 441 of the pushing member 44 of the shaft unit 4 to abut against the inner protrusion 421 of the tubular member 42 of the shaft unit 4, as best shown in FIG. 5. This results in rotation of the tubular member 43 of the shaft unit 4, winding of the screen body 61 on the tubular member 42 of the shaft unit 4 to thereby uncover the sunroof (not shown), rotation of the bobbins 55, and unwinding of each of the ropes 65 from the respective one of the bobbins 55.

As best shown in FIG. 1, the window blind further includes an electric motor unit 42 that is mounted on one of the seat members 41 of the shaft unit 4, and that is operable so as to rotate the shaft member 43 of the shaft unit 4 in the first and second rotational directions (A, B), thereby permitting automated operation of the window blind of this invention.

As best shown in FIG. 2, the window blind further includes a torque transmission unit 7 that prevents slackening of the screen body 61 and the ropes 65. Since the construction of the torque transmission unit 7 is known to those skilled in the art, a detailed description of the same will be dispensed with herein for the sake of brevity.

It is noted that, in an alternative embodiment, the window blind of this invention is applied to a vertical window (not shown), and is dispensed with the slide rails 64, the pulleys 63, and the torque transmission unit 7.

While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements. 

1. A window blind, comprising: a shaft unit including a pair of seat members, a shaft member mounted rotatably on said seat members, a tubular member sleeved rotatably around said shaft member, and formed with an inner protrusion that extends radially and inwardly therefrom, and a pushing member disposed in said tubular member, sleeved securely on said shaft member, and formed with an outer protrusion that extends radially and outwardly therefrom; a flexible screen body wound on said tubular member; a pair of bobbins disposed on opposite sides of said pushing member and sleeved rotatably on said shaft member; a pair of ropes, each of which is wound on a respective one of said bobbins and each of which is coupled to said screen body; and a clutch unit for connecting and disconnecting said shaft member and said bobbins; wherein rotation of said shaft member in a first rotational direction enables said clutch unit to couple said shaft member and said bobbins, thereby resulting in rotation of said bobbins, winding of each of said ropes on the respective one of said bobbins to thereby permit said ropes to pull said screen body, rotation of said tubular member, and unwinding of said screen body from said tubular member, wherein rotation of said shaft member in a second rotational direction opposite to the first rotational direction enables said clutch unit to disconnect said shaft member and said bobbins, and wherein further rotation of said shaft member in the second rotational direction enables said outer protrusion of said pushing member to abut against said inner protrusion of said tubular member, thereby resulting in rotation of said tubular member, winding of said screen body on said tubular member, rotation of said bobbins, and unwinding of each of said ropes from the respective one of said bobbins.
 2. The window blind as claimed in claim 1, further comprising an electric motor unit mounted on one of said seat members, and operable so as to rotate said shaft member in the first and second rotational directions.
 3. The window blind as claimed in claim 1, wherein said clutch unit includes a pair of springs, each of which is sleeved on and is in frictional contact with said shaft member and each of which has an end that is coupled to a respective one of said bobbins, each of said springs contracting in radial inward directions when said shaft member is rotated in the first rotational direction to thereby connect said shaft member and said bobbins, each of said springs expanding in radial outward directions when said shaft member is rotated in the second rotational direction to thereby disconnect said shaft member and said bobbins.
 4. The window blind as claimed in claim 3, wherein said clutch unit further includes a pair of couplers, each of which is sleeved rotatably on said shaft member and is coupled to a respective one of said bobbins, each of said springs being disposed in a respective one of said couplers, said end of each of said springs being connected to the respective one of said couplers.
 5. The window blind as claimed in claim 1, further comprising: a pair of elongate slide rails, each of which has opposite first and second rail ends and is formed with a rail groove therein, each of said seat members being disposed proximate to said first rail end of a respective one of said slide rails; and a pair of pulleys, each of which is mounted rotatably on said second rail end of a respective one of said slide rails, each of said ropes being trained on a respective one of said pulleys.
 6. The window blind as claimed in claim 5, wherein said screen body has lateral ends, each of which is disposed in said rail groove in a respective one of said slide rails, and a front end that interconnects said lateral ends said screen body, said ropes being coupled to said front end of said screen body.
 7. The window blind as claimed in claim 6, further comprising a batten connected to said front end of said screen body, said ropes being connected to said batten. 